Ice making device

ABSTRACT

An ice making device includes an ice making tray, and a drive unit which is structured to turn the ice making tray. In an ice separating operation, the drive unit turns and twists the ice making tray to one side as an ice separation preparatory operation, and then, the drive unit turns and twists the ice making tray to the other side to drop ice pieces from the ice making tray.

CROSS REFERENCE TO RELATED APPLICATION

The present invention claims priority under 35 U.S.C. § 119 to Japanese Application No. 2022-068954 filed Apr. 19, 2022, and the entire content of which is incorporated herein by reference.

TECHNICAL FIELD

At least an embodiment of the present invention may relate to an ice making device and, more specifically, relate to an automatic ice making device structured to automatically produce ice pieces in a refrigerator (freezing chamber).

BACKGROUND

Japanese Patent Laid-Open No. 2013-155926 (Patent Literature 1) discloses an ice making device in which detection of an ice quantity in an ice storage container and detection of an initial position of an ice making tray are performed by one tact switch. In Japanese Patent Laid-Open No. 2014-142093 (Patent Literature 2), an ice making device is disclosed in which an ice quantity in an ice storage container is detected by an ice detection lever having an axial line (rotation center line) parallel to an ice making tray.

Volume of an ice making tray influences an ice-making capacity of an ice making device. In order to maximize an ice-making capacity, it is desirable to increase volume of an ice making tray to the maximum. However, in a case that a size of an ice making tray is simply increased, rigidity of the ice making tray is also increased and thus, there is a risk that ice pieces cannot be sufficiently discharged only by twisting the ice making tray to one side.

Further, when an ice making device is to be started, an arrangement angle of an ice making tray is required to be initialized in a horizontal state. For example, in a case that electric power is supplied again after a power failure, an initialization process may be executed in a state that water is stored in an ice making tray. When an ice making tray is twisted in a state that water is held in the ice making tray, the water may spill from the ice making tray to an ice storage container. Further, unnecessary twisting of the ice making tray is undesirable from a viewpoint of a part life of the ice making tray.

Further, in a refrigerator (freezing chamber), in order to increase a storage capacity of food items and food material which is an original purpose, an arrangement space of an ice making device is required to be minimized. Therefore, it is not easy to simply increase a size of an ice making tray in an existing ice making device.

SUMMARY

In view of the problem described above, at least an embodiment of the present invention may advantageously provide an ice making device which is capable of maximizing a size of an ice making tray with respect to an arrangement space of an ice making device.

According to at least an embodiment of the present invention, there may be provided an ice making device including an ice making tray and a drive unit structured to turn the ice making tray, and the drive unit turns and twists the ice making tray to one side, and then, the drive unit turns and twists the ice making tray to the other side to drop ice pieces from the ice making tray.

A conventional automatic ice making device adopting a method in which an ice making tray is twisted to discharge ice pieces (twisting type) is commonly structured so that an ice making tray is turned to only one side and twisted. On the other hand, according to the embodiment of the present invention, first, the ice making tray is twisted to one side to peel ice pieces off from the ice making tray and, after that, the ice making tray is twisted to the other side sufficiently to discharge the ice pieces. As a result, a large-sized ice making tray can be adopted in comparison with a conventional ice making tray.

Further, in a case that in both ends in an axial line direction of the ice making tray, an end part on a side connected with the drive unit is referred to as a rear end of the ice making tray, and an end part on an opposite side is referred to as a front end of the ice making tray, and the front end and a portion near the front end is referred to as a front end vicinity part, it is preferable that contact parts are provided on a turning path of the front end vicinity part of the ice making tray so that the contact parts are contacted with the front end vicinity part to prevent turning of the front end vicinity part when the ice making tray is turned to the one side and to the other side. When turning of a portion of the ice making tray separated from a support point (connected part with the drive unit) of the ice making tray is prevented, the ice making tray can be efficiently twisted with a small force.

Further, in a case that an arrangement angle of the ice making tray at which the ice making tray holds water is referred to as an ice making position of the ice making tray, it is preferable that the drive unit includes a first detector which is a detector for detecting that the ice making tray is arranged at the ice making position. A detector for detecting that an ice making tray becomes a posture in which the ice making tray is capable of holding water is provided, and the ice making tray is avoided being needlessly twisted.

Further, it is preferable that the ice making device in accordance with the embodiment of the present invention further includes a second detector which is a detector for detecting that the ice making tray is turned to a predetermined arrangement angle which is different from the ice making position. When a detector (first detector) for detecting that the ice making tray is arranged at the ice making position and an another detector (second detector) for detecting that the ice making tray is located at another arrangement angle are separately provided, in other words, when the first detector specializes in detection of the ice making position, it can be detected that the ice making tray is arranged at the ice making position with a further high degree of accuracy.

In this case, it may be structured that the drive unit includes an output part which is connected with the ice making tray to turn the ice making tray, a first lever which is an arm-shaped member whose free end is turned with a turning end as a center, an urging member which urges the first lever to one side in a swing direction of the first lever, and a first lever operation part which is provided in the output part and is capable of contacting with the first lever on a turning path of the first lever operation part to turn the first lever against an urging force of the urging member, and the first detector is a mechanical switch and is disposed within a swing range of the first lever.

Further, it is preferable that the output part is provided with a circular plate part which is a flange-shaped part enlarged in a circular shape and, in a case that one end face of the circular plate part is referred to as a front face, and an end face on an opposite side is referred to as a rear face, the ice making tray is disposed on the front face side of the circular plate part, and the first lever operation part is also provided on the front face side of the circular plate part. In a drive unit of an automatic ice making device, the drive mechanism is commonly disposed on an inner side with respect to an output part (rear face side of the output part) which is connected with an ice making tray. In other words, a front face side of the output part is not so much used except drive of an ice making tray. According to the embodiment of the present invention, a front face side of the output part is positively utilized and thus, an additional function can be mounted on the front face side.

In this case, it may be structured that the ice making device in accordance with an embodiment of the present invention further includes an ice storage part which is a container in which ice pieces are stored, and an ice detection lever which is an arm-shaped member whose free end is capable of turning with a turning end as a center and which detects an amount of ice pieces in the ice storage part. The output part is formed with a teeth part on an outer peripheral face of the circular plate part, and the rear face of the circular plate part structures a driver part of a plane cam mechanism. A rear face side of the circular plate part is disposed with an electric motor which is a drive source, a speed reduction gear train which decelerates rotation of the electric motor to transmit the rotation to the output part, a first conversion shaft which is a shaft body structuring a follower part of the plane cam mechanism and which is connected with the ice detection lever directly or through another power transmission member, a second lever which is an arm-shaped member which structures a follower part of the plane cam mechanism and has a turning end and a free end, the free end being swung in cooperation with turning of the output part, a second detector which is a mechanical switch disposed within a swing range of the second lever and is a detector for detecting that the ice making tray is located at a predetermined arrangement angle (turning angle) which is different from the ice making position; and a second lever operation part which is provided on the first conversion shaft and is structured to prevent a swing of the second lever when the second lever operation part is contacted with the second lever on a turning path of the second lever operation part.

Further, it is preferable that the ice making device in accordance with an embodiment of the present invention further includes an ice storage part which is a container in which ice pieces are stored, and an ice detection lever which is an arm-shaped member whose free end is capable of swinging with a turning end as a center and which detects an amount of ice pieces in the ice storage part. The drive unit includes an output part which is connected with the ice making tray to turn the ice making tray, a first conversion shaft which is a shaft body turned in cooperation with turning of the output part, and a second conversion shaft which is a shaft body turned in cooperation with turning of the first conversion shaft and connected with the ice detection lever. An axial line (turning center line) of the first conversion shaft is extended at a right angle with respect to a direction of an axial line of the output part, an axial line of the second conversion shaft is extended at a right angle with respect to a direction of the axial line of the first conversion shaft, and the axial line of the output part and the axial line of the second conversion shaft are parallel to each other. As a result, the turning center line of the ice detection lever can be disposed at an arbitrary position while the turning center line of the ice detection lever is kept in parallel with the turning center line of the output part.

In this case, it is preferable that the ice detection lever is provided with a swing part which is extended in a perpendicular direction with respect to the axial line of the second conversion shaft, and a lifting and lowering part which is horizontally extended in a perpendicular direction from a tip end of the swing part. When the swing part of the ice detection lever is set as long as possible, its end (lifting and lowering part) can be largely moved up and down with a small turning operation. Further, in order to enhance detection accuracy of an ice quantity in the ice storage part, it is desirable that the ice detection lever is contacted with a reference face on a line or a face, not a point, for determining whether an ice quantity is in a full state or not. In the embodiment of the present invention, the lifting and lowering part is horizontally extended and thus, an ice quantity can be always detected on a line or a face.

In this case, it is preferable that the swing part is arranged on a lower side with respect to a position of the axial line of the output part. In addition, in a case that an arrangement angle that the ice making tray holds water is referred to as an ice making position of the ice making tray, it is preferable that the lifting and lowering part is arranged at a position lower than an upper face of the ice making tray located at the ice making position. When the ice detection lever is lowered and lifted at a position adjacent to the ice making tray (position horizontally arranged with respect the ice making tray), the ice making tray is installed in a space except a space occupied by the ice detection lever in a limited arrangement space in a refrigerator. In other words, a part of an arrangement space in a horizontal direction of the ice making tray is occupied by the ice detection lever. However, when a lifting and lowering range of the ice detection lever is set in a range lower than an upper face of the ice making tray, a size in the horizontal direction of the ice making tray can be maximized.

Further, in a case that a position at which the ice making tray is disposed with respect to the drive unit is referred to as a front side of the drive unit, it may be structured that the ice making tray is disposed on the front side of the drive unit, and the ice detection lever is also disposed on the front side of the drive unit.

Further, it is preferable that the first conversion shaft and the second conversion shaft are connected with each other by bevel gears.

Effects of the Invention

As described above, according to the present invention, a size of the ice making tray can be maximized with respect to an arrangement space of the ice making device.

Other features and advantages of the invention will be apparent from the following detailed description, taken in conjunction with the accompanying drawings that illustrate, by way of example, various features of embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will now be described, by way of example only, with reference to the accompanying drawings which are meant to be exemplary, not limiting, and wherein like elements are numbered alike in several Figures, in which:

FIG. 1 is a perspective view showing an outward appearance of an ice making device in accordance with an embodiment of the present invention.

FIGS. 2A through 2D are schematic views showing a flow of an ice separating operation which is performed by an ice making device.

FIG. 3 is a rear view showing a power transmission path of a drive unit.

FIG. 4 is a perspective view showing a connection structure of a first conversion shaft, a second conversion shaft and an ice detection lever.

FIGS. 5A and 5B are perspective views showing a structure of a cam gear.

FIG. 6A is a perspective view showing a structure of a first conversion shaft and FIG. 6B is its side view.

FIG. 7A is a plan view showing a structure of a second lever and FIG. 7B is its perspective view.

FIG. 8 is a rear view showing a drive mechanism when an ice making tray is located at an ice making position.

FIG. 9 is a rear view showing a drive mechanism when an ice separation preparatory operation is performed.

FIG. 10A is a rear view showing a drive mechanism when an ice detection operation is performed and FIG. 10B is its side view.

FIG. 11 is a timing chart showing operations of respective parts when an ice separating operation is continued and interrupted.

FIG. 12 is a rear view showing a drive mechanism when a discharge operation is performed.

FIG. 13 is a rear view showing a drive mechanism after ice pieces have been discharged.

FIGS. 14A and 14B are front views showing an initializing operation of an ice making device.

FIG. 15 are a timing chart showing changes of outputs of a first switch and a second switch in an initializing operation.

DETAILED DESCRIPTION

An ice making device in accordance with an embodiment of the present invention will be described below with reference to the accompanying drawings. An ice making device 90 described below is a device which is installed in a freezer chamber of a refrigerator not shown and to which water is supplied from the refrigerator to automatically produce ice pieces.

An “upper and lower” direction in the following descriptions is a direction parallel to the “Z”-axis of coordinate axes described in FIG. 1 , and the “Z1” side is an “upper” side and the “Z2” side is a “lower” side. A “front and rear” direction is a direction parallel to the “X”-axis of the coordinate axes, and the “X1” side is referred to as a “front” side and the “X2” side is referred to as a “rear” side. Similarly, a “right and left” direction is a direction parallel to the “Y”-axis of the coordinate axes, and the “Y1” side is referred to as a “right” side and the “Y2” side is referred to as a “left” side. Further, a “horizontal” direction means an “X-Y” plane direction in the coordinate axes.

(Entire Structure)

FIG. 1 is a perspective view showing an outward appearance of an ice making device 90. The ice making device 90 is a so-called twist type automatic ice making device which is structured to discharge ice pieces by twisting an ice making tray 20. The ice making device 90 includes an ice making tray 20 made of resin which is provided with a plurality of cells (water storing compartment) and a drive unit 10 which is a motor unit for turning the ice making tray 20. The drive unit 10 and the ice making tray 20 are supported by a frame 91 which is a frame body installed in a freezing chamber. Further, the drive unit 10 includes an ice detection lever 31 which is an arm-shaped member for detecting an amount of ice pieces in an ice storage part 92 described below.

(Schematic Ice Separating Operation)

FIGS. 2A through 2D are schematic views showing a flow of an ice separating operation (operation for discharging ice pieces from the ice making tray 20) which is performed by the ice making device 90.

FIG. 2A is a view showing a state that the ice making tray 20 is located at an “ice making position” which is an arrangement angle where water is held. A control device which is provided in the refrigerator monitors a temperature of the ice making tray 20 by a thermistor (not shown) which is attached to its lower face and, when it is detected that the temperature of the ice making tray 20 has reached a predetermined value, an ice separating operation is started. FIGS. 2B through 2D are views showing an ice separating operation performed by the ice making device 90.

FIG. 2B is a view showing an “ice separation preparatory operation” performed by the ice making device 90. The “ice separation preparatory operation” is an operation in which the ice making tray 20 is preliminarily twisted so that ice pieces can be easily peeled off from the ice making tray 20. When the temperature of the ice making tray 20 has reached a predetermined value, first, the drive unit 10 turns the ice making tray 20 in the “CCW” direction in the drawing. A front end of the ice making tray 20 is formed with a shaft part 23 supported by a shaft hole of the frame 91 at a center of the ice making tray 20, and a first protruded part 21 and a second protruded part 22 which are protruded parts protruded to a front side are formed at the front end of the ice making tray 20 on a right side and a left side with respect to the shaft part 23. The frame 91 is provided with a first contact part 911 and a second contact part 912 on turning paths of the first protruded part 21 and the second protruded part 22 and, when the first protruded part 21 and the second protruded part 22 are turned in the “CCW” direction and the “CW” direction, the first contact part 911 and the second contact part 912 are contacted with the first protruded part 21 and the second protruded part 22 to restrict turning. Turning in the “CCW” direction of the ice making tray 20 is prevented by the first contact part 911 and the second contact part 912 at the substantially same time as the start of the turning. The drive unit 10 further turns the ice making tray 20 by 10 degree in the “CCW” direction from the state that the ice making tray 20 is prevented from turning to twist the ice making tray 20 (cam gear turning angle −10° in FIG. 11 ). As a result, ice pieces are peeled off from the ice making tray 20 to some extent.

FIG. 2C is a view showing an “ice detection operation” performed by the ice making device 90. The “ice detection operation” is an operation in which an amount of ice pieces in the ice storage part 92, which is a container for storing ice pieces, is detected to determine whether an ice separating operation is continued or interrupted (canceled) After the ice separation preparatory operation has been performed, when the ice making tray 20 starts turning in the “CW” direction in the drawing, the ice detection lever 31 is moved down to an inside of the ice storage part 92 in cooperation with the turning of the ice making tray 20. In this case, when the ice detection lever 31 is moved down lower than a predetermined reference face, it is determined that an amount of ice pieces is insufficient and thus, the ice separating operation is continued. On the other hand, when the movement of the ice detection lever 31 is restricted by stored ice pieces before the ice detection lever 31 reaches the reference face, it is determined that an amount of ice pieces in the ice storage part 92 is in a full state and the ice separating operation is canceled.

FIG. 2D is a view showing a discharge operation of ice pieces which is performed by the ice making device 90. In a case that an amount of ice pieces in the ice storage part 92 is insufficient, the ice making device 90 continues the ice separating operation. When the ice making tray 20 is continuously turned in the “CW” direction in the drawing, the first protruded part 21 and the second protruded part 22 of the ice making tray 20 are contacted with the second contact part 912 and the first contact part 911 of the frame 91. The drive unit 10 further turns the ice making tray 20 from the state by several tens degree in the “CW” direction to twist the ice making tray 20. As a result, ice pieces in the ice making tray 20 are discharged to the ice storage part 92 (cam gear turning angle 160° in FIG. 11 )

As described above, the drive unit 10 of the ice making device 90 turns the ice making tray 20 to one side (“CCW” direction in the drawing) and twists the ice making tray 20 and, after that, the drive unit 10 turns the ice making tray 20 to the other side (“CW” direction in the drawing) and twists the ice making tray 20 to discharge ice pieces from the ice making tray 20. A conventional twist type automatic ice making device is commonly structured so that an ice making tray is only turned to one side and twisted. In the ice making device 90 in this embodiment, first, the ice making tray 20 is twisted to one side to peel ice pieces off from the ice making tray and, after that, the ice making tray 20 is sufficiently twisted to the other side to discharge the ice pieces. Therefore, in comparison with a conventional ice making tray, a large-sized ice making tray having a high rigidity can be adopted. Further, in the ice making device 90 in this embodiment, the first protruded part 21 and the second protruded part 22 of the ice making tray 20 and the first contact part 911 and the second contact part 912 of the frame 91 are provided at positions apart from a support point of the ice making tray 20 (connection part with the drive unit 10) and thereby, the ice making tray 20 can be efficiently twisted by a small force.

(Schematic Drive Mechanism)

FIG. 3 is a rear view showing a power transmission path of the drive unit 10. FIG. 3 is an explanatory view mainly showing a mechanism on a rear side of the drive unit 10. The ice making device 90 receives supply of electric power from the refrigerator in which the ice making device 90 is installed to perform various predetermined operations according to signals from a control device mounted on the refrigerator.

The drive unit 10 includes a stepping motor 81 (electric motor) which is a drive source, a cam gear 40 which is an output part for turning the ice making tray 20, and a first conversion shaft 50 and a second conversion shaft 32 which swing the ice detection lever 31 in cooperation with an operation of the cam gear 40.

The cam gear 40 is provided with a gear part 41 which is a circular plate part in a flange shape that is enlarged in a circular shape. The gear part 41 is formed with a teeth part on its outer peripheral face and functions as a spur gear. Rotation of the stepping motor 81 is decelerated by a speed reduction gear train and is transmitted to the gear part 41 of the cam gear 40. The speed reduction gear train in this embodiment is structured of a worm gear 811 attached to an output shaft of the stepping motor 81, a first gear 82, a second gear 83 and a third gear 84. Each of the first through third gears is a composite gear structured so that a large diameter gear and a small diameter gear are overlapped and integrated with each other in an axial line direction. A large diameter gear of the first gear 82 is a worm wheel which is paired with the worm gear 811.

A rear face 41 b of the gear part 41 structures a driver part of a plane cam mechanism. The first conversion shaft 50 is a shaft body which structures a follower part of the gear part 41. The second conversion shaft 32 is a shaft body which is turned in cooperation with turning of the first conversion shaft 50 to swing the ice detection lever 31. An axial line (turning center line) of the first conversion shaft 50 and an axial line of the cam gear 40 are set in a twisted positional relationship and, in a plan view, the axial line of the first conversion shaft 50 is extended at a right angle with respect to a direction of the axial line of the cam gear 40. The axial line of the first conversion shaft 50 and the axial line of the second conversion shaft 32 are disposed on the same plane and intersect perpendicular to each other.

Further, the rear face 41 b of the gear part 41 is contacted with a second lever 72 which is another follower part. The second lever 72 switches “ON” and “OFF” of a second switch 71 (second detector) which is a mechanical switch according to a turning angle of the cam gear 40 and a turning angle of the first conversion shaft 50 (in other words, a lowering angle of the ice detection lever 31). The refrigerator monitors an output of the second switch 71 and, when an ice quantity in a freezing chamber is sufficient (fully stored state with ice pieces), the ice separating operation performed by the drive unit 10 is canceled and, when the ice quantity is insufficient, the ice separating operation is continued.

(Structure of Ice Detection Lever)

FIG. 4 is a perspective view showing a connection structure of the first conversion shaft 50, the second conversion shaft 32 and the ice detection lever 31. The ice detection lever 31 in this embodiment is connected with the second conversion shaft 32. A structure of the ice detection lever 31 for maximizing a size of the ice making tray 20 will be described below with reference to FIGS. 1 through 4 .

As shown in FIG. 4 , the first conversion shaft 50 and the second conversion shaft 32 are connected with each other at a right angle through bevel gears 59 and 321 which are provided at respective one ends in their axial line directions. The other end (front end) of the second conversion shaft 32 is provided with a connection part 322 for the ice detection lever 31, and a connection part 311 of the ice detection lever 31 is connected with the connection part 322. In other words, a turning center of the second conversion shaft 32 is also a swing center of the ice detection lever 31. As described above, the axial line of the first conversion shaft 50 intersects the axial line of the cam gear 40 at a right angle in a plan view, and the axial line of the first conversion shaft 50 also intersects the axial line of the second conversion shaft 32 at a right angle in a plan view. As a result, the axial line of the cam gear 40 and the axial line of the second conversion shaft 32 (and the axial line of the ice detection lever 31) are disposed so as to be parallel to each other. In the ice making device 90 in this embodiment, a turning direction (direction of the axial line) of the cam gear 40 is successively converted by 90° by using the first conversion shaft 50 and the second conversion shaft 32, and consequently, the axial line of the ice detection lever 31 is disposed in parallel with the axial line of the cam gear 40. As a result, the axial line of the ice detection lever 31 can be disposed at an arbitrary position while the axial line of the ice detection lever 31 and the axial line of the cam gear 40 are kept in parallel with each other.

The ice detection lever 31 is provided with a swing part 312 which is extended in a perpendicular direction with respect to the axial line of the second conversion shaft 32, and a lifting and lowering part 313 which is horizontally extended from a tip end of the swing part 312. As shown in FIG. 1 , both of the ice making tray 20 and the ice detection lever 31 are disposed on a front side with respect to the drive unit 10. Further, as shown in FIG. 2 , the swing part 312 of the ice detection lever 31 is disposed lower than a position of the shaft part 23 of the ice making tray 20, in other words, lower than a position of the axial line of the cam gear 40, and the swing part 312 is extended so as to cross a front face of the cam gear 40. As described above, in the ice making device 90 in this embodiment, a position of a turning end of the ice detection lever 31 is adjusted by using the first conversion shaft 50 and the second conversion shaft 32, and a length of the swing part 312 of the ice detection lever 31 is set to be long. As a result, in the ice detection lever 31 in this embodiment, its tip end (lifting and lowering part 313) can be largely moved up and down at a small turning angle.

Further, as shown in FIG. 2A, the lifting and lowering part 313 of the ice detection lever 31 is disposed at a position lower than an upper face of the ice making tray 20 located at the ice making position. In other words, a position of the lifting and lowering part 313 which is raised uppermost is lower than an upper face of the ice making tray 20. If the lifting and lowering part 313 of the ice detection lever 31 is structured so as to move upward to a position above an upper face of the ice making tray 20, the ice making tray 20 is required to be disposed in a limited arrangement space except a space occupied by the ice detection lever 31 in the refrigerator. In other words, an arrangement space in a horizontal direction of the ice making tray 20 is partly occupied by the ice detection lever 31. When a lifting and lowering range of the ice detection lever 31 is set in a position lower than an upper face of the ice making tray 20, a size in the horizontal direction of the ice making tray 20 can be maximized. Further, the ice making device 90 in this embodiment is capable of performing the ice separation preparatory operation in addition to a common ice separating operation and thus, a large-sized ice making tray 20 is preferably utilized.

Further, in order to enhance detection accuracy of an ice quantity in the ice storage part 92, it is desirable that the ice detection lever 31 is contacted with a reference face on a line or a face, not a point, for determining whether an ice quantity is in a full state or not. In the ice detection lever 31 in this embodiment, the lifting and lowering part 313 is horizontally extended as shown in FIG. 1 and thus, an ice quantity can be always detected on a line or a face.

(Details of Drive Mechanism)

Details of respective parts which structure a drive mechanism of the drive unit 10 will be described below with reference to FIGS. 5A through 7B.

FIGS. 5A and 5B are perspective views showing a structure of the cam gear 40. FIG. 5A is a perspective front view showing a front face side of the cam gear 40, and FIG. 5B is a perspective rear view showing a rear face side of the cam gear 40. As shown in FIG. 5A, the cam gear 40 is provided on its front face side with an ice making tray fitting shaft 42, which is a shaft part in a rectangular shape that is connected with a rear end part of the ice making tray 20, and a frame fitted shaft 43 which is a circular shaft part that is supported by a bearing not shown provided in the frame 91. A front face 41 a of the gear part 41 is formed with a first lever operation part 63 which is a protruded part for operating a first lever 62 described below.

As shown in FIG. 5B, a rear face side of the cam gear 40 is provided with a tube part 44 in a cylindrical tube shape at a center of the cam gear 40. A lowering stop sleeve 49 described below is attached to an outer face of the tube part 44. The rear face 41 b of the gear part 41 is formed with a first cam 45 and a second cam 46 which are ribs structuring driver parts of a plane cam mechanism. The first cam 45 is a rib in a roughly circular ring shape. The first conversion shaft 50 is turned along a shape of an inner peripheral face of the first cam 45. The first cam 45 is provided with a recessed slope 451 which is a slope stretched to an outer side in a radial direction in a predetermined range in a circumferential direction. The second cam 46 is a rib which is formed along a periphery of the rear face 41 b of the gear part 41. The second lever 72 is turned along a shape of an inner peripheral face of the second cam 46. The second cam 46 is provided with a former side protruded slope 461 and a latter side protruded slope 462 which are slopes on which the second lever 72 rides, an intermediate recessed slope 463 which is a downward slope provided between the protruded slopes 461 and 462, and a terminal recessed slope 464 which is a downward slope continuing in a clockwise turning direction in the drawing from the latter side protruded slope 462.

FIG. 6A is a perspective view showing a structure of the first conversion shaft 50 and FIG. 6B is its side view. The first conversion shaft 50 is provided with a tip end shaft 51 and an intermediate shaft 58 which are shaft parts supported by a case 11 (see FIG. 1 ) of the drive unit 10. The first conversion shaft 50 is provided with a plurality of protruded parts on a body part in a columnar shape. These protruded parts are structured from the “Y1” side toward the “Y2” side of a sliding part 52 which is a cam follower contacting with the first cam 45, a turning stopping part 53 which is abutted with the lowering stop sleeve 49 described below to prevent turning of the first conversion shaft 50 in the “CW” direction in FIG. 6B, a spring receiving part 54 which is always urged toward an upper side (in other words, so as to turn the first conversion shaft 50 in the “CW” direction) by a coil spring 541 (see FIG. 3 ), a first positioning piece 55 which is inserted into a recessed part not shown of the frame 91 to restrict a turning range of the first conversion shaft 50, a second lever operation part 56 which is contacted with the second lever 72 to operate a swing angle of the second lever 72, and a second positioning piece 57 which is contacted with a partition wall not shown of the frame 91 to prevent movement of the first conversion shaft 50 in the “Y2” direction. Further, a “Y2” side end part of the first conversion shaft 50 is provided with a bevel gear 59 which is connected with the second conversion shaft 32.

FIG. 7A is a plan view showing a structure of the second lever 72 and FIG. 7B is its perspective view. The second lever 72 is an arm-shaped member having a shaft part 729 which is a turning center, and a plurality of free ends which are turned with the shaft part 729 as a turning center. The second lever 72 is, as the free ends, provided with a sliding part 721 which is a cam follower contacting with the second cam 46, a switch operation part 722 which is always urged to a side of the second switch 71 by a coil spring 79, and a turning restriction part 723 which is inserted into a recessed part 111 of the case 11 to restrict a turning range of the second lever 72.

(Details of Ice Separating Operation)

An ice separating operation of the ice making device 90 will be described further in detail below with reference to FIGS. 8 through 13 .

FIG. 8 is a rear view showing the drive mechanism when the ice making tray 20 is located at the ice making position (cam gear turning angle 0° in FIG. 11 ). In this case, the sliding part 52 of the first conversion shaft 50 is located outside the recessed slope 451 of the first cam 45 and thereby, the ice detection lever 31 is raised upward. The sliding part 721 of the second lever 72 does not ride on the former side protruded slope 461 yet and thus, the second switch 71 is set in an “ON” state.

FIG. 9 is a rear view showing the drive mechanism when the ice separation preparatory operation is performed. When a temperature of the ice making tray 20 has reached a predetermined value, or alternatively, when a certain period of time has elapsed from a start of a previous ice separating operation, the drive unit 10 first turns the ice making tray 20 by a fixed amount in the “CW” direction in the drawing to twist the ice making tray 20 (cam gear turning angle 0° to −10° in FIG. 11 ). In this case, the sliding part 52 of the first conversion shaft 50 is still located outside the recessed slope 451, and the ice detection lever 31 is kept in a raised state. Further, the sliding part 721 of the second lever 72 still does not ride on the former side protruded slope 461 and thus, the second switch 71 is kept in an “ON” state.

FIG. 10A is a rear view showing the drive mechanism when the ice detection operation is performed and FIG. 10B is its side view. FIG. 11 is a timing chart showing operations of respective parts when the ice separating operation is continued and canceled. When the ice separation preparatory operation has completed, the drive unit 10 turns the cam gear 40 in the “CCW” direction in the drawing. As a result, the sliding part 52 of the first conversion shaft 50 enters the recessed slope 451 and the ice detection lever 31 is lowered. When the ice detection lever 31 starts to be lowered, the sliding part 721 of the second lever 72 simultaneously rides on the former side protruded slope 461 and the second switch 71 is switched to an “OFF” state (cam gear turning angle 5° in FIG. 11 ).

When lowering of the ice detection lever 31 is not prevented by ice pieces, the swing part 312 is turned more than 30° and, when the lifting and lowering part 313 is lowered exceeding the reference face within the ice storage part 92, in other words, when the sliding part 52 of the first conversion shaft 50 has reached a deep part of the recessed slope 451, the second lever operation part 56 of the first conversion shaft 50 is contacted with the switch operation part 722 of the second lever 72 to press the switch operation part 722 in a direction separated from the second switch 71. When the cam gear 40 is turned to a position where the sliding part 52 of the first conversion shaft 50 is located at the deep part of the recessed slope 451, the sliding part 721 of the second lever 72 reaches a position of the intermediate recessed slope 463 of the second cam 46. In this case, when the ice detection lever 31 has been sufficiently lowered and a return of the switch operation part 722 of the second lever 72 (return to the second switch 71 side) is restricted by the second lever operation part 56 of the first conversion shaft 50, the second switch 71 is kept in an “OFF” state and the cam gear 40 continues turning in the “CCW” direction (cam gear turning angle 35° through 55° in FIG. 11 ).

In this embodiment, when lowering of the ice detection lever 31 is prevented by stored ice pieces and the first conversion shaft 50 is not turned sufficiently, the second lever operation part 56 of the first conversion shaft 50 does not reach the switch operation part 722 of the second lever 72 and, as a result, the sliding part 721 of the second lever 72 is moved along the intermediate recessed slope 463 to switch the second switch 71 to an “ON” state. When the control device of the refrigerator detects that the second switch 71 is switched to an “ON” state within a predetermined time period, the control device cancels the ice separating operation and returns the ice making tray 20 to the ice making position without discharging ice pieces.

FIG. 12 is a rear view showing the drive mechanism at the time of the discharge operation of ice pieces. When the second switch 71 has passed through the intermediate recessed slope 463 while the second switch 71 is kept in an “OFF” state, the sliding part 52 of the first conversion shaft 50 rides on the opposite side cam portion with respect to the recessed slope 451 and thereby, the ice detection lever 31 is lifted up. In this case, the sliding part 721 of the second lever 72 has ridden on the latter side protruded slope 462 and thus, even when the second lever operation part 56 of the first conversion shaft 50 does not press down the switch operation part 722 of the second lever 72, the second switch 71 is kept in an “OFF” state. When the ice making tray 20 has been fully twisted in the “CCW” direction in the drawing and ice pieces has been discharged, the sliding part 721 of the second lever 72 is moved to the terminal recessed slope 464 and the second switch 71 is switched to an “ON” state (cam gear turning angle 160° in FIG. 11 ). The refrigerator detects completion of discharge of ice pieces based on the switching of the second switch 71.

FIG. 13 is a rear view showing the drive mechanism after ice pieces have been discharged. When discharge of ice pieces has been finished, the ice making device 90 returns the ice making tray 20 to the ice making position. In this embodiment, the tube part 44 of the cam gear 40 is attached with the lowering stop sleeve 49 in a cylindrical tube shape. The lowering stop sleeve 49 is provided with a body part formed with a slit 492 and a protruded part 493 which is protruded to an outer side from the body part. The lowering stop sleeve 49 is not fixed to the tube part 44 and is turned together with the tube part 44 by frictional resistance. A turning range of the protruded part 493 is restricted by the case 11, and the protruded part 493 is reciprocated within the movable range in the turning direction of the cam gear 40. After ice pieces have been discharged, when the cam gear 40 is turned in the “CW” direction in the drawing, the sliding part 52 of the first conversion shaft 50 is going to be moved to the recessed slope 451. However, in this case, the turning stopping part 53 of the first conversion shaft 50 is abutted with the protruded part 493 of the lowering stop sleeve 49 and the first conversion shaft 50 is prevented from being turned. Therefore, the ice detection lever 31 is not lowered during the return operation.

(Initializing Operation)

FIGS. 14A and 14B are front views showing an initializing operation of the ice making device 90. FIG. 15 are a timing chart showing changes of outputs of the first switch 61 and the second switch 71 in an initializing operation. In this embodiment, an “initializing operation” (initialization) is an operation that the ice making tray 20 is rearranged at the ice making position, for example, when electric power is supplied for the first time after installation of a refrigerator, when electric power is supplied again after a power failure, and the like. Further, also in a return operation after the ice separation operation has been performed, the initializing operation may be performed when the ice making tray 20 is to be arranged at the ice making position. The initializing operation of the ice making device 90 will be described below with reference to FIGS. 14A, 14B and 15 .

The drive unit 10 includes a first switch 61 (first detector), which is a mechanical switch for detecting that the ice making tray 20 has been arranged at the ice making position, and a first lever 62 for switching the first switch 61 between an “ON” state and an “OFF” state. The first lever 62 is an arm-shaped member whose free end is turned with its turning end as a turning center, and the first switch 61 is disposed within a swing range of the first lever 62. The first lever 62 is always urged in a direction so that the first switch 61 is turned to an “ON” state by a torsion spring 69 which is an urging member.

Further, the gear part front face 41 a of the cam gear 40 is formed with a first lever operation part 63 which is a protruded part that is capable of contacting with the first lever 62 on a turning path to turn the first lever 62 against an urging force of the torsion spring 69. The first lever operation part 63 is contacted with the first lever 62 when the ice making tray 20 is arranged at the ice making position and, when the ice making tray 20 has passed the ice making position, the first lever operation part 63 switches the first switch 61 to an “OFF” state (cam gear turning angle 0° in FIG. 15 ).

As described above, according to the drive unit 10 in this embodiment, a lifting and lowering range of the ice detection lever 31 is set in a range lower than an upper face of the ice making tray 20 and thereby, a size in the horizontal direction of the ice making tray 20 is maximized. Therefore, rigidity of the ice making tray 20 in this embodiment is increased in comparison with a common ice making tray and thus, there is a risk that ice pieces cannot be sufficiently discharged by merely twisting the ice making tray 20 to one side. In order to prevent the problem, the ice making tray 20 is structured to be twisted to one side and, in addition, to the other side and thereby, ice pieces are prevented from being left in the ice making tray 20. In a case that the ice making tray 20 is structured to be capable of being twisted in both directions, the ice making tray 20 may be needlessly twisted at the time of the initializing operation. Specifically, when the ice making tray 20 is twisted in a state that water is held in the ice making tray 20, the water may spill out from the ice making tray 20 to the ice storage part 92. Further, an unnecessary twisting of the ice making tray 20 is undesirable from a viewpoint of a part life of the ice making tray 20. According to the ice making device 90 in this embodiment, a detector is separately provided for detecting that the ice making tray 20 is located at the ice making position and thus, the ice making tray 20 is prevented from being twisted needlessly. Further, in the ice making device 90 in this embodiment, the detector (first switch 61) for detecting that the ice making tray 20 is located at the ice making position and the detector (second switch 71) for detecting that the ice making tray 20 is located at another arrangement angle (turning angle) are separately provided. In other words, the first switch 61 specializes in detection of the ice making position and thus, it can be detected that the ice making tray 20 is located at the ice making position with a high degree of accuracy.

Further, in a drive unit of a commonly used automatic ice making device, the drive mechanism is disposed on an inner side with respect to an output part (on a rear face side of the output part) connected with an ice making tray. In other words, a front face side of the output part is not so much used except driving of an ice making tray. According to the ice making device 90 in this embodiment, a front face side of the cam gear 40 (output part) is positively utilized and thus, an additional function can be mounted without increasing a space occupied by an automatic ice making device.

While the description above refers to particular embodiments of the present invention, it will be understood that many modifications may be made without departing from the spirit thereof. The accompanying claims are intended to cover such modifications as would fall within the true scope and spirit of the present invention.

The presently disclosed embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims, rather than the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. 

What is claimed is:
 1. An ice making device comprising: an ice making tray; and a drive unit which is structured to turn the ice making tray; wherein the drive unit turns and twists the ice making tray to one side, and then, the drive unit turns and twists the ice making tray to an other side to drop ice pieces from the ice making tray.
 2. The ice making device according to claim 1, further comprising: contact parts, being provided on a turning path of a front end vicinity part of the ice making tray, wherein in a case that, in both ends in an axial line direction of the ice making tray, an end part on a side connected with the drive unit is referred to as a rear end of the ice making tray, and an end part on an opposite side is referred to as a front end of the ice making tray, and the front end and a portion near the front end is referred to as the front end vicinity part, and the contact parts are structured to be contacted with the front end vicinity part to prevent turning of the front end vicinity part when the ice making tray is turned to the one side and to the other side.
 3. The ice making device according to claim 1, wherein in a case that an arrangement angle of the ice making tray at which the ice making tray holds water is referred to as an ice making position of the ice making tray, the drive unit comprises a first detector which is a detector detecting that the ice making tray is arranged at the ice making position.
 4. The ice making device according to claim 3, further comprising: a second detector which is a detector detecting that the ice making tray is turned to a predetermined arrangement angle which is different from the ice making position.
 5. The ice making device according to claim 3, wherein the drive unit comprises: an output part which is connected with the ice making tray to turn the ice making tray; a first lever which is an arm-shaped member whose free end is turned with a turning end as a center; an urging member which urges the first lever to one side in a swing direction of the first lever; and a first lever operation part which is provided in the output part and is capable of contacting with the first lever on a turning path of the first lever operation part to turn the first lever against an urging force of the urging member, wherein the first detector is a mechanical switch and is disposed within a swing range of the first lever.
 6. The ice making device according to claim 5, wherein the output part comprises a circular plate part which is a flange-shaped part enlarged in a circular shape, in a case that one end face of the circular plate part is referred to as a front face, and an end face on an opposite side is referred to as a rear face, the ice making tray is disposed on a front face side of the circular plate part, and the first lever operation part is also provided on the front face side of the circular plate part.
 7. The ice making device according to claim 6, further comprising: an ice storage part which is a container in which ice pieces are stored; and an ice detection lever which is an arm-shaped member whose free end is capable of swinging with a turning end as a center and which detects an amount of ice pieces in the ice storage part, wherein the output part is formed with a teeth part on an outer peripheral face of the circular plate part, and a rear face of the circular plate part structures a driver part of a plane cam mechanism, the rear face side of the circular plate part is disposed with: an electric motor which is a drive source; a speed reduction gear train which decelerates a rotation of the electric motor to transmit the rotation to the output part; a first conversion shaft which is a shaft body structuring a follower part of the plane cam mechanism and which is connected with the ice detection lever directly or through another power transmission member; a second lever which is an arm-shaped member which structures a follower part of the plane cam mechanism and has a turning end and a free end, the free end being swung in cooperation with turning of the output part; a second detector which is a mechanical switch disposed within a swing range of the second lever and is a detector for detecting that the ice making tray is located at a predetermined arrangement angle which is different from the ice making position; and a second lever operation part which is provided on the first conversion shaft and is structured to prevent a swing of the second lever when the second lever operation part is contacted with the second lever on a turning path of the second lever operation part.
 8. The ice making device according to claim 1, further comprising: an ice storage part which is a container in which ice pieces are stored; and an ice detection lever which is an arm-shaped member whose free end is capable of swinging with a turning end as a center and which detects an amount of ice pieces in the ice storage part, wherein the drive unit comprises: an output part which is connected with the ice making tray to turn the ice making tray; a first conversion shaft which is a shaft body turned in cooperation with turning of the output part; and a second conversion shaft which is a shaft body turned in cooperation with turning of the first conversion shaft and connected with the ice detection lever, wherein an axial line of the first conversion shaft is extended at a right angle with respect to a direction of an axial line of the output part, an axial line of the second conversion shaft is extended at a right angle with respect to a direction of the axial line of the first conversion shaft, and the axial line of the output part and the axial line of the second conversion shaft are parallel to each other.
 9. The ice making device according to claim 8, wherein the ice detection lever comprises: a swing part which is extended in a perpendicular direction with respect to the axial line of the second conversion shaft; and a lifting and lowering part which is horizontally extended in a perpendicular direction from a tip end of the swing part.
 10. The ice making device according to claim 9, wherein the swing part is arranged on a lower side with respect to a position of the axial line of the output part.
 11. The ice making device according to claim 9, wherein in a case that an arrangement angle that the ice making tray holds water is referred to as an ice making position of the ice making tray, the lifting and lowering part is arranged at a position lower than an upper face of the ice making tray at the ice making position.
 12. The ice making device according to claim 8, wherein in a case that a position at which the ice making tray is disposed with respect to the drive unit is referred to as a front side of the drive unit, the ice making tray is disposed on the front side of the drive unit, and the ice detection lever is also disposed on the front side of the drive unit.
 13. The ice making device according to claim 8, wherein the first conversion shaft and the second conversion shaft are connected with each other by bevel gears. 